Post traumatic stress disorder (PTSD) is a prevalent anxiety disorder marked by behavioral, physiologic, and hormonal alterations. Significant impairment across several domains of functioning is common. Recently, there has been increased interest and research utilizing functional magnetic resonance imaging (fMRI) to examine specific brain activation (or deactivation) in subjects with PTSD. Though recent studies have confirmed differences in various areas of brain function between PTSD and healthy controls, only one study has examined if effective psychological intervention may also modify brain functions. The goal of the proposed K23 Career Development Award is twofold. First, to provide the candidate, Steven E. Bruce, Ph.D., with additional training in neuroimaging methodology and analysis to become a leader in neuroimaging clinical trials. Second, the proposal will examine the neural correlates of PTSD symptom reduction in individuals with PTSD. Specifically, we propose to examine neuroimaging data from 30 participants with PTSD at two points, before and after completion of cognitive processing therapy (CPT), a highly effective, 12-session cognitive behavioral treatment for PTSD. An additional 30 healthy control participants will be recruited and used as a comparison group. Neuroimaging data will focus on amygdala and prefrontal cortex activity, and these regions will be compared after cognitive behavioral therapy. Specifically, we hypothesize that participants who respond to treatment compared to those who do not respond, will differ in amygdala and prefrontal cortex activity. We also hypothesize that these differences between responders and non-responders will be evident prior to treatment. That is, we hypothesize that patterns of activation at baseline will predict response to treatment. Significant changes in brain activity as a result of successful treatment could have profound implications for the development and refinement of psychological treatments for PTSD. Similarly, predicting treatment outcome from baseline neuroimaging will enable clinicians to further personalize treatment approaches to maximize potential outcomes for individuals suffering from PTSD.